Advanced Custom Fields: Extended WordPress: remote code execution (RCE)
Advanced Custom Fields: Extended WordPress
Remote code execution (RCE) in the Advanced Custom Fields: Extended WordPress component. Threat level: Critical (CVSS 9).
Who is affected
This vulnerability affects: Advanced Custom Fields: Extended WordPress. If you use this component on your site, check the version and update it as soon as possible.
How dangerous
Rating: Critical, CVSS 9 out of 10. Critical flaws are often exploited en masse within hours of disclosure.
What this flaw is
Remote code execution (RCE) is the most dangerous class of flaw. It lets an attacker run their own code on your server, usually remotely and without logging in.
In practice it means a full takeover of the site and server: content replacement, data theft, backdoor installation. Such flaws are exploited en masse and automatically, often within hours of disclosure.
Score breakdown (CVSS vector)
What the CVSS 9 rating means in practice:
- The attack can be carried out remotely, over the internet.
- No login or account required.
- Requires no action from the victim.
- The impact may reach beyond the vulnerable component itself.
- At risk: data confidentiality, integrity (data can be altered), site availability.
Weakness class: CWE-94.
How to fix: remote code execution (RCE)
- Update the vulnerable component to the patched version immediately, this is the highest-priority class of flaw.
- If no patch exists yet, deactivate the component or take the site into maintenance mode until it does.
- Assume possible compromise: search the site for unknown PHP files (especially in wp-content/uploads), unexpected admin accounts and scheduled tasks.
- After patching, rotate all secrets: admin passwords, database password, and the WordPress salts in wp-config.php.
- If you find signs of a break-in, restore from a known-clean backup rather than just deleting suspicious files.
Prefer not to do this yourself? We will handle the update, check for signs of a break-in and secure the site. Write to us →
Frequently asked questions
Does this vulnerability affect my site?
It affects sites that use Advanced Custom Fields: Extended WordPress. Check whether you have this component installed and which version, the flaw only applies to the vulnerable version range. You can verify it in under a minute with our free vulnerability scanner.
How do I check whether I have the vulnerable version?
In your admin panel (in WordPress: Plugins / Themes) check the installed version of Advanced Custom Fields: Extended WordPress and compare it with the vendor advisory that names the fixed version. If it is lower, or you are not sure, run our scanner, which reads the versions visible in the site code.
How urgently should I react?
This is a Krytyczna-severity flaw, so treat it as urgent, high-impact vulnerabilities are often exploited automatically within hours of disclosure. Update as soon as possible.
What if a patch is not available yet?
Until a fix ships, reduce the exposure: temporarily disable the vulnerable component, restrict access to the affected functionality, or add a WAF rule blocking the vulnerable request. Keep a current off-site backup and watch for signs of a break-in.
Is updating alone enough?
If the site has not been attacked yet, updating to the patched version closes the hole. If there are already signs of compromise (unknown files, new admin accounts, redirects), the update does not undo the break-in, you also need to clean the site and rotate passwords and the WordPress salts.
Does this flaw affect your site?
We will run a free audit: we check versions, plugins, and configuration, and tell you plainly whether you are safe.
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